Roller bar electrode



FIG. 1 is a prospective view of a roller bar electrode showing the new design;

FIG. 2 is a rear view of the roller bar electrode thereof.

FIG. 3 is a lateral view of the roller bar electrode thereof; and,

FIG. 4 is a front view of the roller portion of the roller bar electrode. 

We claim the ornamental design for a roller bar electrode, as shown and described. 